The invention relates to ball throwing device for tennis balls, which are conveyed by a feeder into the space between two rollers mounted on parallel axes and are ejected by rotating the rollers. Both rollers are disposed on a carrier which can be swivelled in the plane of the rollers, i.e. transverse to the axes, and the spacing of the axes of the rollers is variable.
To the extent that such devices have been described to date, e.g. in DE-A1-32 10 828, such description leaves totally open the manner by which the spacing of the axes of the rollers can be varied.